An equipment such as an oil-fired space heater, a gas-fired space heater or the like includes a control section which is provided with electric parts such as a switch and a variable resistor for driving the equipment, a luminous display section for displaying a state of operation of the equipment, and the like. A conventional equipment control panel generally includes a circuit board which has such electric parts mounted thereon and is supported on a frame made of synthetic resin. The frame on which the circuit board is thus supported is fixed on a casing of the equipment in such a manner that the electric parts which are required to be externally operated and the luminous display means are positioned in an opening provided at the casing of the equipment. Alternatively, the frame may be fixed on a wall of a room in which the equipment is placed while being away from the equipment. Also, the circuit board is covered on a surface of a portion thereof positionally corresponding to the electric parts such as the switch and the like which are required to be externally operated with an insulating cover member exhibiting at least flexibility. Between the circuit board and the insulating cover member is arranged an insulating spacer.
Such construction of the conventional equipment control panel causes mounting of the equipment control panel on the casing of the equipment to require to form the casing with an opening of an increased size. Unfortunately, this not only renders design of the casing of the equipment troublesome but causes a portion of the casing on which the equipment control panel is to be mounted to be subject to positional restriction. Also, it renders mounting of the equipment control panel on the casing of the equipment troublesome.
In addition, equipments such as a forced flue oil-fired space heater (fan heater) and the like are affected by high-frequency noise to be generated from various electric units placed in proximity to the equipment and elements arranged in the equipment as well. More particularly, When the equipment control panel is constructed into a structure like a flat plate, a circuit pattern on the circuit board is caused to act as an antenna, to thereby facilitate introduction of the high-frequency noise into the equipment control panel, so that the noise causes malfunction of a control unit arranged in the equipment.
In order to avoid the problem, it would be considered that a shield casing is grounded while substantially covering the circuit pattern on the circuit board with the shield casing, to thereby keep the noise from entering the equipment through the wiring pattern of the equipment control panel, resulting in protecting the control unit of the equipment. Unfortunately, such an approach is not applied to the equipment control panel when it is constructed so as to be fixed on the equipment while being kept exposed on a surface of the equipment, because such construction fails to permit the whole equipment control panel to be covered with the shield casing. In such a case, it is possible to form a conductive shield layer on a front surface of an insulating spacer positioned on the wiring pattern of the circuit board or a rear surface of an insulating cover sheet member in a manner to be opposite to the circuit pattern of the circuit board, to thereby prevent any external noise from entering the equipment. However, it was found that such a conductive shield layer fails to prevent malfunction of the control unit or a failure in operation thereof due to discharge of static electricity charged on the insulating cover sheet member. Also, it was found that when the equipment control panel is provided therein with electronic components such as an IC for signal processing and the like, discharge of static electricity charged on the insulating cover sheet member causes a failure in operation of the electronic components.
Accordingly, it is an object of the present invention to provide an equipment control panel which is capable of preventing a failure in operation of a control unit due to discharge of static electricity charged on an insulating cover sheet member.
It is another object of the present invention to provide an equipment control panel which is capable of being readily mounted on an outer surface of a casing of an equipment, facilitating connection thereof to a control unit arranged in the equipment, and preventing a failure in operation of the control unit due to discharge of static electricity.
It is a further object of the present invention to provide an equipment control panel which is capable of being reduced in thickness and mounted on an outer surface of a casing of an equipment.
It is another object of the present invention to provide an equipment control panel which is capable of preventing any noise generated from an equipment from entering the panel.